The invention relates to a connector for optical fibres, notably monomode fibres. The connector includes a receptacle which is accomodated in a housing sleeve and in which there can be inserted at least one connector pin. The connector pin is provided with a collar which is axially pressed against the end face of the receptacle by a screw cap which can be screwed onto the end of the housing sleeve. The receptacle is provided with a radial vent hole at the area of the end face of the inserted connector pin, which vent hole opens into a free space which extends in the axial direction between the receptacle and the housing sleeve and wherefrom air can escape to the environment.
Notably connectors for monomode fibres require accurate and tight fits between the connector pin and the receptacle. Vents must be provided in order to allow the escape of air from the interior of the receptacle when the connector pin is inserted. In the device described above, these vents are not situated at the area of the fit between the connector pin and the receptacle, because ducts situated at that area would affect the bearing strength of the connector pin and allow for penetration of dirt, moreover, they would also necessitate a complex manufacturing process. Therefore, it is attractive to construct the vents in the described manner.
According to the previous proposal, the threaded portion of the housing sleeve covered by the screw cap was provided with a radial vent hole wherethrough the air could escape from the free space to the environment via the thread. In order to ensure that the outer vent hole indeed opens into the free space between the receptacle and the housing sleeve, the exterior of the housing sleeve had to be subjected to a complex grinding operation so as to form an annular free space. Moreover, loose particles from the thread could be forced into the outer vent hole and reach, via the further vents, the space for accomodating the connector pin.